When a hint is requested, the solver uses a set of solving
techniques to find the next step to solve the puzzle. For most puzzles
a hint can be provided, however for some extremely difficult puzzles
the solver will not be able to provide a hint and will return the
message "No Hints Available".

This does not mean that the puzzle cannot be solved logically, it
means that the limitations of the solver have been reached.

The solver returns this message when there is no solution for a
puzzle. This can be due to an incorrectly specified cell value or an
invalid candidate. Please recheck your input, clear your candidates
and retry. If the solver still cannot solve the puzzle, then the
puzzle is invalid.

Some puzzles have multiple solutions. Since puzzles with multiples
solutions cannot be solved logically, they are technically invalid. It
is a good idea to check if a puzzle has a unique solution using the
"Check" function before starting to solve it.

3504 Free puzzles

Puzzle Number:

Paste the numbers into the input field below or enter
them directly. Press 'Fill Grid' to seed the grid.

How to use

This solver offers a number of features
to help you improve your solving skills and practice solving
strategies. First enter the numbers of the sudoku directly in the
grid or enter them via the "Load" and "Seed" buttons. You can then
completely solve the puzzle or use the appropriate buttons to check
the validity of the puzzle, get tips for step by step solving and
much more. See the button descriptions below for more information.

This is what the buttons do:

Solve Cell: Solves a single cell.
Click in the cell you want to solve first, then click this button

Solve:Solves the Sudoku puzzle
completely

Solve Partially:Solves the puzzle
partially according to the preference settings

Check: Checks if the Sudoku puzzle
is valid and can be solved

Unique Check: Checks if the Sudoku
has a unique solution

Rate Difficulty: Displays a
difficulty rating of the Sudoku

Hint: Get a hint.

Candidates On/Off:Show/Hide
candidate values in empty cells

Seed: Opens an input area from
which the grid can be loaded. You can paste a puzzle into the input
area.

Load: Uploads a saved sudoku
puzzle into the grid

Save: Generates a file containing
the current values in the Sudoku grid for downloading

Print: Opens a new window from
which the sudoku puzzle can be printed

Clear: Clears the puzzle

Simple: Seeds the grid with a
random simple sudoku puzzle

Easy: Seeds the grid with a random
easy sudoku puzzle

Medium: Seeds the grid with a
random medium sudoku puzzle

Hard: Seeds the grid with a random
hard sudoku puzzle

Editing Candidates:

First display the candidates by clicking on the
"Show Candidates" button

Delete candidate

Click on the candidate and it will disappear

Undelete candidate

Click on the position where the candidate is normally
displayed and it will reappear